The control of the synthesis of ribosomes and RNA polymerase in E. coli is being investigated. The binding of RNA polymerase to the promoter for the str transcription unit is being studied. DNA containing deletions of the promoter or point mutations in the promoter will be used to prove that the observed binding is specific. The rate of synthesis and the accumulation of RNA polymerase subunits in rho mutants will be measured. In addition, the levels of mRNA for the Beta and Beta' subunits of RNA polymerase in these mutants will be measured by hybridization. The effect of purified RNA polymerase subunits on the synthesis of Beta and Beta' in an in vitro DNA-dependent protein synthesizing system will also be investigated.